Clock



Sept. 28, 1948. A. N. WOODRUFF 2,450,254

CLOCK Filed Oct. 23, 1946 2 Sheets-Sheet 1 1977'0 R/VEVS.

p 1943- A. N. WOODRUFF 2,450,264

CLOCK Filed Oct. 23, 1946 2 Sheets-Sheet 2 AUTO/457575.

, was; sa 2a,- 1948- UNI ED STATES "PATENT OFFICE CLOCK Albert N. Woodruff, Washington, D. 0. Application October 23, 1946, Serial No. 705,136

2 Claims. 1

This invention relates to improvements in clocks wherein means are provided for readily determining local tim in any part of the world.

The clock is adapted to be used with a time zone chart on which the various time zones of the world are indicated and is an improvement over the clock illustrated and described in my earlier Patent No. 2,305,508,- December 15, 1942.

Y The principal object of the present invention is to provide a simple and emcient means, which can be added to a conventional clock without modifying the operational parts thereof for moving a. graduated zone dial, which is graduated in degrees and time zones, to any selected time zone, in conjunction with the simultaneous movement of the hour and minute hands of the clock whereby the local time may be accurately determined in the selected time zone.

Other objects and advantages will be apparent on considering the following specification in the light of the accompanying drawing wherein:

Figure 1 is a front elevational view of the inillustrating the parts of the clock attachment,

these parts being drawn out of true relationship so that the working may be better understood.

Referring more particularly to the drawings wherein like reference characters designate like parts throughout the several views, the numeral 1 indicates generally a conventional clock which has been modified, in accordance with the invention, to indicate the local time in various parts of the world.

The dial 2, Figure 5, consists of an appropriate sheet I preferably white, backed by two flat plates 4 and 5 preferably of metal. These plates are firmly secured together by any conventional means such as rivets 6. The periphery of the dial 2 carries the conventional markings I for indi-' cating minutes. These markings preferably have the rivets 6 passing therethrough as illustrated in Figure 5 to add to the general appearance of the dial 2.

An inner circumferential series of fairly large numerals 8 will designate the local time. These numerals extend from 1 to 12 according to custom exceptthat numeral 6 has been omitted to provide a circular sight opening 9 in the dial and backing plates through which numerals appearing on a graduated ring dial may be observed, as presently described. A second circumferential series of numerals I0 is placed on the dial 2 be tween the minute markings I and the hour numerals 8. The numerals l0 run consecutively from 13 to 24, with the latter being omitted to accomodate an elongated opening II. The numerals iii are in the same radial positions as numerals 8, so that numeral 18 is positioned directly below the sight opening. The numerals 10 are only used when it is desired to indicatetime on a 24 hour basis, as used for example, by the armed forces, rather than on the conventional 12 hour basis. When using the clock for indicating time on a 24 hour basis use is made of an annular day and night disc'l2 which is viewed through the opening 9. One half of the disc I2 is painted red and the other half painted white, and the disc is of such dimensions with respect to the opening 9 that only a portion thereof can be seen through opening 8 at any time. The operating mechanism, which will be later described in detail, is such that the day and night disc I2 will make one complete revolution for every two revolutions made by a convention-a1 hour hand l3 of the clock I. Due to the arrangement of the disc and hand I3, it will be apparent that, when the hour hand is in the 12 hour or 24 hour position, the red and white portions of disc 12 will be viewed through orening 9. During any other position of the hour hand, the disc l2 will either show all or predeterminately one color depending on whether it is the first 12 hours (A. M.) of the day or the last 12 hours (P. M.) In the present embodiment of the invention the color white will indicate the first 12 hours of the day while the color red will indicate the second 12 hours or the P. M. period. In reading the time when using the 24 hour system, if the hands of the clock indicate 3 o'clock and the day and night disc 12 appears white, the time would be 0300, whereas if the disc l2 appears red, the time would be 1500.

Positioned behind the dial 2 is a graduated circle I the graduations of which are visible through opening II. The graduated circle [4 is rotated manually, as presently described. The circle It consists of a ring dial l5 which is backed by a metal plate It. The two are cemented together, and the ring dial is inscribed as follows. A circumferential series of numerals ll nearest the inside perimeter of the graduated circle 14 denotes local time zones. These zones are desirably boxed off in a circular grid I2 and run consecutively from 1 to 24 without interruption and are adapted to appear at the bottom of the dial opening H.

A second circumferential series of numerals l3 appears next to the outside perimeter of the graduated circle |4. These numerals are intended to indicate degrees of longitude east of Greenwich. They comprise the whole circumference of the globe and are based on only one direction of progressing from Greenwich, namely toward the east. To this end said numerals conveniently start at and then are stepped oil by increases of 15 until the zero or 360 position is reached. On the same plan the local time zones are numbered from Greenwich toward the east, and logically so because the time periods of any given day and in any given locality build progressively as the globe rotates toward the east.

The time zone indicator on the graduated circle I4 is preferably used in conjunction with a time zone map, not shown, which is marked oil. beginning from Greenwich towards the east, into 24 time zones numbered from 1 to 24. Thus, each zone covers an area of 15 longitude. Since Greenwich will be in the center of the last or time zone 24 and because the longitude of Greenwich is 360, time zone 1 will be in the area between 730 and 2230 east of Greenwich. As the time zones are stepped off by lines drawn parallel to the meridians of the map, each zone covers 15 longitude. For example, the limits of time zone 24 will be 35230' east and 730 east. If it is desired to set the clock for a particular locality, the locality is first selected on the above mentioned time zone map and the ring dial l5 turned by mechanism to be hereinafter described, until the numeral 19 of numerals I1 is centrally positioned in the opening I However, if the longitude of a locality is known and it is desired to obtain the local time in that locality, the ring dial I5 is turned until the longitude of the locality appears in the opening I The ring dial i5 is then further adjusted until the time zone, which occurs below the particular longitude, is centrally positioned in the opening II. The graduated circle i4 is operatively connected, through a suitable means to be described, to the minute and hour hands of the clock so that the latter will be turned with the graduated circle to indicate the local time in the time zone appearing in the opening I At this point it is desired to explain that the international date line is eliminated insofar as the use of this clock is concerned. Instead of reading the meridian to meet half way around the globe at the international date line according to present practice, only a uni-directional reading is contemplated herein, namely, east of Greenwich, thus accounting for the progressive rotation of the numerical series 24. Having described the various indicia on the clock face and the purpose of the graduated circle i4, I shall now describe in detail the various operational parts of my invention.

The driving means for the graduated circle I 4 is shown as adapted to a conventional clock opially aligned with and mounted on shaft 2 I. The sleeves 23 and 24 are common in clock manufacture and are usually adapted to carry the minute and hour hands respectively, the clock mechanism being such as to make the inner sleeve 23 rotate once for every 60 revolutions of the shaft 2|, that is, once every hour, whereas the outer sleeve 24 rotates once every 12 hours, that is, once for every 12 revolutions of sleeve 23, or once for every 720 revolutions of the shaft 2|. As previously stated, the shaft 2| and the respective sleeves 23 and 24 and the mechanism for rotating the same are standard construction in clocks and form no part of this invention except wherein they are used to drive the particular operating mechanism which will now be described.

A plate 23, preferably of metal and rigidly secured by any suitable means to the clock mechanism 20, is formed with an opening 26 to permit of the passage of shaft 2| and sleeves 23 and 24 therethrough. Rigidly secured to the plate 25 are guide pins 21 having collars or flanges 28 adapted to engage the smooth inner edge of the ring dial i5 so that the latter is guided and supported solely by the guide pins and flanges.

Driving power for the minute and hour hands and for the day and night disc I2 is obtained directly from the outer sleeve 24 which makes one complete revolution in every 12 hours. A gear 23 having 40 teeth is keyed to sleeve 24 so as to rotate therewith. Freely and rotatably mounted on sleeve 24 under gear 23 is a larger gear Ill having 72 teeth which carries a rotatable shaft 10 on the outer periphery thereof. Mounted on shaft 10 and keyed together are gears 3| and 32 with gear 3| having 10 teeth and meshing with gear 23. Gear 32 has 36 teeth and meshes with a 12 toothed gear 33 which is keyed to a second inner sleeve 34 mounted on shaft 2| and to which sleeve 34 is secured a minute hand 35. The gear ratio through the gear train 23, 3|, 32 and =33 is such that for every one complete revolution of gear 29, the gear 33 must make 12 complete revolutions.

Metal plates 4 and 5 have respective cut away portions 33 and 31 which together with a flat disc 33, rigidly secured to the outer or top face of the dial 2, form a gear housing adapted to contain the operational gears for the day and night disc l2 and the hour hand l3. Mounted on disc 38 is a shaft 35 which carries gears 40 and 4| which are keyed together. Gear 40 is provided with 36 teeth and meshes with the previously described gear 33, and the 10 toothed gear 4|, which rotates with gear 40, is in turn in mesh with and 40 toothed gears 42 and 43 respectively. Gear 42 carries the day and night disc l2. If desired, the surface of gear 42 may be painted half red and half white in which case it would serve as the day and night disc. Gear 43 is rigidly secured to a second outer sleeve 44 encasing the second inner sleeve 34 and carrying the hour hand I 3.

The distance between the upper ends of shaft 2| and sleeves 34 and 44 is sufficient to enable the proper spacing of the second, minute and hour hands. It should be noted that the gear ratio through the gear train 33, 40, 4| and 43 is such that gear 43 will make one complete revolution for every 12 complete revolutions of gear 33. the gear 42 must make one complete revolution every 24 hours, the gear ratio through the gear train 33, 40, 4| and 42 is such that gear 42 will Since the day and night disc i2 and make one complete revolution for every 24 complete revolutions of gear I8. 1

Thus, it will be apparent that, as the clock mechanism 20 operates, the second, minute and hour hands will respectively be rotated relative to each other to indicate the time in the conventional manner. That is, the second hand 22 i rotated directly by shaft 2| and the minute and hour hands are rotated by outer sleeve 24 in turn rotated by the clock mechanism Ill; the minute hand I! is rotated through gear train 29, ll. 32 and I3 and the hour hand M is rotated through gear train 29, ll, l2, ll, 40 4| and 43.

The ring dial I! and graduated circlel4 are manually rotated in conjunction with the clock hands to indicate the local time in any selected time zone. To effect this rotation, a shaft 45 carrying a thumb wheel 40 on the extended outer end thereof is journalled in spaced bearings 41 and 44 formed on brackets 49 and Ill secured to plate 25. The innermost bearing 48 is a step bearing against which the shoulder of a pinion gear II, carried by the inner end of shaft 45, rests. The pinion gear I, meshes with a gear 52. The gear 52 is keyed to a shaft 54 which extends through bracket 4! and plate 25. A 26 toothed gear 5! and a 32 toothed gear 56 are rigidly secured to the shaft 54 so as to turn as a unit with gear 52.

' The gear 98 meshes with the external teeth of a 193 tooth ring gear 51 which is fixedly secured by any suitable means such as rivets not shown. to the back of the ring plate It. Thus, manual rotation of the thumb wheel 46 will produce a turning of the graduated circle l4. It is necessary to move the local hour hand I3 and minute hand 3! simultaneously with the above described operation and this is accomplished by the following gears. The gear It, the primary purpose of which is to turn the 72 toothed gear 30, meshes with an idler gear 88 and which is necessitated 1 by the requirement of having both hour and minute hands It and" move in the same direction as the graduated circle l4 depending upon the direction of rotation of the thumb wheel 46.

It will be understood that one clockwise or counterclockwise revolution of the graduated scale l4 will be accompanied by two revolutions of the hour hand II. Thus, the primary function of the 26 toothed gear I! and the 32 toothed gear 5. is to rotate the local hour hand It twice to every one revolution of the graduated scale l4. The hour hand I! is thereby retained in step with the graduated scale, keeping in mind that the 24: hour amplitude of the hour hand it must be coordinated with the 360 angularity of the graduated circle l4.

It should be particularly pointed out at this time theimportance of'the 26 teeth of gear 55.

A 24 toothed gear was first used in place of the 26 toothed gear. However, it was noted that for a complete 'rotation'of the ring dial the hour hand lost two hours. In order to bring the hour hand in step with thering dial, it was found necessary to increase the number of teeth of gear Ill to 26 teeth. As originally constructed, the ring gear ll was provided with 192 teeth, but it was noted that,,for anycomplete revolution of the ring gear, the minute and hour hands were minutes out of step. This was corrected by increasing the number of teeth from 192 to 193.

The driving coordination between the graduated circle l4 and thehour hand It is traced,

from gears 50 and N, with the latter being rotated as a unit through the gear 92 when the aliases I pinion ii is revolved by means of the thumb wheel 46. Gear actuates idler gear I! which turns gear 30 so that planetary motion of the gear set it and 32 mounted on gear 30 around the relatively stationary gear 29 causes the pinion gear 33 to be rotated. Since any turning of pinion gear 33 is transmitted directly to the minute hand 35 through sleeve 34, as previously described, and through gear train 33, 40,, 43 and.

sleeve 44 to the hour hand It, it-will be appreciated that both the minute hand II and the hour hand II will be rotated. As the gear 56 is in mesh with and rotates the ring gear 51 which carries the graduated circle l4, it is apparent that the minute and hour-hands II and ll of the clock I will rotate in conjunction with the graduated circle i4 as the thumb wheel 40 is turned. Since the ratios of movement between ring gear 51 and pinion gear 33 are such, due to the relation of gears 51, 56, II, 59, 30, ll, 29, I2 and II. that one revolution of gear 51 will occur for every twenty-four (24) revolutions of gear 33, and the hour and minute hands I! and 35 are thereby kept in step with graduated circle 14. Therefore, as the graduated circle is rotated by operation of thumb wheel 46 to bring a selected time zone into the opening Ii, the hour and minute hands of the clock will also be rotated to give that a person in possession of a clock embodying my invention is located in Washington, D. C., and listening to a radio program at 8:05 P. M., such as a news broadcast direct from Ankara, Turkey. The local time will, of course, be indicated by the hour and minute hands I! and 25 and the red portion of the day and night disc will be visible through the opening 9 indicating that it is 8:05 P. M. When viewed through opening I I, the graduated circle I 4 will show time zone 19 and 285 east longitude as the central meridian of time zone 19. By referring to the chart, hereinbefore described, it will readily be determined that Ankara, Turkey, is at a longitude of approximately 26 east and is in time zone 2.- Thumb wheel 46 is thereupon rotated until time zone 2 is observed through opening ll. As previously described the hands of the clock will move in conjunction with the graduated disc i4 and the day and night disc i2. Thus, when zone 2 appears centrally positioned in opening H, the clock hands will indicate 3:05 which would be the time of that moment in Ankara and the day and night disc will appear white-through opening 8 thus indicating that it is 3:05 in the moming, I

Having thus described my invention what I I claim is:

1.v An attachment for a clock mechanism having a central driven shaft, a second hand mounted on said shaft, inner and outer sleeves arranged on the upper end of said shaft, minute and hour hands mounted on said sleeves, means for driving said shaft and sleeves, a dial having two sets of numerals thereon for indicating time on a twelve and twenty-four hour basis, an indicator disc associated with said dial whereby said hour hand will denote ante meridian and post meridian periods of time, inner and outer sleeves arranged on the lower end of said shaft, means for rotating said hands and disc, said means including a gear carried by said lower outer sleeve, a second gear carried by said lower inner sleeve, a first gear set adapted to transmit driving motion of said first gear to said second gear, a second gear set comprising a large gear and a small gear, said large gear meshing with and being rotated by said second gear, and said small gear meshing with and being adapted to rotate a third and a fourth gear, said fourth gear being carried by one of said upper sleeves and adapted to move said hour hand, the ratio of said gears being such that for every rotation of said lower outer sleeve and said first gear said second gear will make twelve revolutions and said third and fourth gears will respectively make one half and one revolutions.

2. An attachment for a clock mechanism having driving means, a central shaft driven by said means and carrying a, second hand, inner and outer sleeves mounted on the upper end of said shaft and carrying minute and hour hands, said attachment comprising a plate secured to said clock mechanism, an annular dial supported in spaced relation to said plate, said dial having numerals thereon for indicating time zones and longitude, a second dial member mounted between said annular dial and said plate, said secand dial having numerals thereon for indicating time On a twelve and twenty-four hour basis, an indicator disc associated with one of said dials for indicating ante or post meridian periods of time, inner and outer sleeves arranged on the lower end of said shaft, means including a gear carried by said lower outer sleeve, a second gear carried by said lower inner sleeve, a first gear set adapted to transmit motion of said first gear to said second gear, a second gear set comprising a large gear and a small gear, said large gear meshing with and being rotated by said second gear, said small gear meshing with and adapted to rotate a third and fourth gears, said fourth gear being carried by one of said upper sleeves and adapted to move said hour hand, the ratio of said gears being such that for every revolution of said lower outer sleeve and the first gear said second gear will make twelve revolutions and the respective third and fourth gears will make one half and one revolution, a second shaft supported by said plate and having a gear formed on one end thereof, a first train of gears associated with and driven through rotation of said second shaft and last mentioned gear for driving said annular dial and said second gear whereby said hour and minute hand and said indicator disc are rotated, the ratio of movement transmitted by said last mentioned gears being such as to cause two complete revolutions of said hour hand for every revolution of said annular disc.

ALBERT N. WOODRUFF.

REFERENCE S CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 302,497 Kcating July 22, 1884 2,305,508 Woodruff Dec. 15, 1942 

